BEGIN {
    sub main_package_vars {
        foreach(@_) {
            eval "sub $_ {
                my \$p = shift;
                \$p->{$_} = \$_[0] if \@_;
                \$p->{$_};
            }"
        }
    }
}

##</code><code>##

    sub main_package_vars {
        foreach my $name (@_) {
            no strict 'refs'; *{ $name } = sub {
                my $p = shift;
                $p->{$name} = $_[0] if @_;
                $p->{$name};
            }"
        }
    }

##</code><code>##

BEGIN {
    eval "*package_vars2 = \*main::main_package_vars";
    *package_vars3 = \*main::main_package_vars;
}

##</code><code>##

package_vars3( qw(one two three) );